Step-by-step explanation:
volume of sphere = 288
based on formula, V = 4/3πr³
288 = 4/3(3.14)r³
288 = 4.187(r³)
r³ = 288/4.187
r =
r = 4.09
= 4.1
Answer:
x= -1/9
Step-by-step explanation:
6+2x=5-7x
-2x. -2x
6=5-9x
-5. -5
1=-9x/-9
-1/9=x
The average time of the 20 athletes who did not qualify for the final is 11.2 seconds .
<u>Step-by-step explanation:</u>
Here we have , Twenty-eight athletes participate in a 100-meter race. The time of each athlete is measured during the qualification round. The average time is 11 seconds. The 8 athletes with the fastest time qualified for the final. The average time of these 8 athletes is 10.5 seconds. Let's have equations for this:
where are athletes
⇒
⇒
⇒
⇒ , where m is average time of the 20 athletes who did not qualify for the final.
⇒
⇒
⇒
∴ The average time of the 20 athletes who did not qualify for the final is 11.2 seconds .
N^2 - n = 90
n^2 - n - 90 = 0
(n - 10)(n + 9) = 0
n - 10 = 0
n = 10
n + 9 = 0
n = -9
answer is : n = 10 and n = -9